windowing becomes NAN when dcm file has no window width/level tags

[1isten]

this bug happens in the latest main branch, https://volview-dev.kitware.app

try with a dcm file that has no width/level tags, i.e., in the useWindowingConfigInitializer file the firstTag will be undefined

hold and drag mouse to change the windowing, it becomes NAN and the image becomes invisible:

[PaulHax]

Thanks for catching that. Can you share a DICOM file with this problem?

[1isten]

@PaulHax here are some:
603.000000-PET-CT SERIES-72118.zip

another way to get such dicom file, is just use the Paint tool of volview, save the segmentation as dcm file format, that saved dcm file can also reproduce this issue

[PaulHax]

Looks like the cause is the multicompoent RGB nature of the image files.